Ice slides moved more mass per man than any other method available at the time.

While visiting and enjoying the architecture of the Forbidden City in China, three researchers wondered how large rocks weighing many hundreds of tons were transported to the site more than 500 years ago. A relaxing holiday became a science project, and in a paper just published, the researchers reveal calculations showing that the most likely means of achieving this feat was by using wooden sleds on artificial ice paths.

Built in the early 15th century, the Forbidden City consists of an imperial palace and nearly a thousand buildings. It served as the figurative center of China’s capital city. During the researchers' visit, Howard Stone, professor of mechanical and aerospace engineering at Princeton University, saw a sign that mentioned the use of an artificial ice path to transport the enormous stones used in the city.

However, a look at the history of technology in China revealed that wheels existed in China since the 4th century BC. Why, then, would there still be a need to use human-pulled sleds? “That is when we began to investigate and calculate,” said Stone.

With the help of Jiang Li, a mechanical engineer at the University of Science and Technology Beijing who studies tribology (the study of friction), the researchers dug into the literature to find more details on the effort involved in transporting these stones. One document said that a monolithic slab weighing 112 tons was moved over 70 km to Beijing in 1557.

Chinese-wheeled carriages would not have been able to transport such blocks, even with the technology of the late 1500s. Another option would be to use wooden rollers, but that would require creating a smooth surface on tricky, winding roads.

Calculations published in the Proceedings of the National Academy of Sciences reveal that pulling such stones over bare ground at a rate mentioned in the historical text would require more than 1,500 men. Even sliding the stone on bare ice would need 330 men. However, one solution from the researchers, which involved tobogganing the stones on wooden planks and lubricating the path with cold water, would only need 50 men for that load.

A weather analysis of the last 2,000 years in China finds that the average January temperature in Beijing in the 15th and 16th century was about –4°C, which would have been enough to create and maintain artificial ice paths. While historical records reveal that more than a million workers were involved in the construction, details about the construction activity are hard to find.

The Chinese were at the forefront of the study of friction at the time. Chariots preserved with the Terracotta Army, which is more than 2,000 years old, showed that they even used wheel bearings to reduce friction.

“It’s a wonderful story and a good historical analysis,” said Thomas Mathia, a tribologist at French National Scientific Research Center. “But it’s just a hypothesis.”

Regardless of whether or not the researchers are able to determine whether tobogganing massive stones played a part in the construction of the Forbidden City, for Stone the pleasure was in following up the story. “Recognising the degrees of planning and implementation used more than 500 years ago for such a massive undertaking was humbling.”

During the researchers' visit, Howard Stone, professor of mechanical and aerospace engineering at Princeton University, saw a sign that mentioned the use of an artificial ice path to transport the enormous stones used in the city.

When I clicked on the article, I had assumed that the researchers came up with some clever explanation for an unsolved mystery. I certainly didn't expect researchers to find their answer on a sign at the site they were visiting.

Monumental tasks can be accomplished quite easily when you rule with the divine right and you have a mass of poor peasants looking for work.

From what I have read in my limited capacity in researching the economic system of ancient China, the people who built these were likely free, specialized workers employed by the central government or militia members in suburban Beijing. The Ming great wall was partly constructed by contracted private merchants, partly by the solders who were garrisoned there - Imagine how difficult it would be for uneducated farmers to be taught to do what stone masons and carpenters do for a living.

Don't presume that because there was imperial rule, everybody had to be miserable.

Demonstrates that "ancient man" doesn't mean "idiot men". Now can I assume that going down hill wasn't problematic?

We have a hard time seeing how they did some things back then simply because they saw the world differently than we do today so they saw solutions to problems which would simply never occur to us given modern thinking.

Demonstrates that "ancient man" doesn't mean "idiot men". Now can I assume that going down hill wasn't problematic?

The 14th century is hardly 'ancient'. This isn't all that impressive, compared to, say, the construction of the Egyptian pyramids etc., but it's still interesting.

I think the challenges involved are quite different. The best analogy would probably be a modern skyscraper and Cristo Redentor. The Pyramids are big piles of stone in the desert. The Forbidden Palace was built in a ancient metropolis to begin with. Timber and stone supply needed to be managed, work would have to be spread out in order to not interfere with the court or normal commerce in the city. Some of the great halls are amazing examples of how wood can be crafted into enormous structures and stand for centuries.

Both are great examples of how people without modern technology deal with problems. As it stands they do quite well and find solutions we cannot imagine.

I'm just flabbergasted by the statement that "wheels existed in China since the 4th century BC". If they weren't in China before that time, that seems incredibly late in history for their introduction, especially in a civilization that is stereotyped to have been ahead of the curve in many areas through much of its history.

Demonstrates that "ancient man" doesn't mean "idiot men". Now can I assume that going down hill wasn't problematic?

Referring to the most sophisticated civilisation in the 16th century as ancient is pretty insulting to be honest.

Why is it insulting? I agree, ancient is not the correct word for something as near-present as the 14th century, but ancient is just a subjective term meaning, more or less, old. There is nothing pejorative about it. It doesn't imply primitiveness or anything.

Just kidding. By the way, about the whole ancient thing, we must remember that they were using the most modern technology they had available, and China was probably at the forefront on many technological developments at the time. It's not like some really smart human being couldn't figure out that water freezes and provides a smoother path, so you could put water wherever you wanted a path and it would freeze in winter. It's interesting to learn more about how old civilizations with a different view of the world solved problems in different ways than us, but not all that surprising, at least to me. They weren't animals you know, they already had entire cities going on.

Now, another question is why when the Chinese civilization is so old and the western civ is so young, did the western Civ out pace the Chinese technology wise?

There are huge swaths of books and research dedicated to this topic.

Short answer: War.

Europe's constant wars and fights between each other spured technology growth in a time when the Chinese Civilization reach unification. There are a lot of groups all over China that are not Chinese, but for the most part all of China unified under one government and inovation slowed.

Instead of investing in technology, the rich kept accumulating more wealth instead of stirring up innovation.

Constant war in europe created;Faster, stronger, and larger ships because constant sea battles caused each side to keep trying to out do the otherStronger lighter armor because armies still had to get around and be protectedStronger and more fortified forts, castles, and general building structure While gun powder came from China, Europe took to making many more and stronger guns to continue fighting.

Technology such as planes were not created for war, but were certainly industrialized and mass produced for war.

Demonstrates that "ancient man" doesn't mean "idiot men". Now can I assume that going down hill wasn't problematic?

The 14th century is hardly 'ancient'. This isn't all that impressive, compared to, say, the construction of the Egyptian pyramids etc., but it's still interesting.

Seeing the final product in person I am impressed. It's not just the weigh, the 112 ton stone is a relatively long and narrow stone. That they could move something that heavy without breaking or cracking it and the technological constraints they had is impressive in my book.

Monumental tasks can be accomplished quite easily when you rule with the divine right and you have a mass of poor peasants looking for work.

From what I have read in my limited capacity in researching the economic system of ancient China, the people who built these were likely free, specialized workers employed by the central government or militia members in suburban Beijing. The Ming great wall was partly constructed by contracted private merchants, partly by the solders who were garrisoned there - Imagine how difficult it would be for uneducated farmers to be taught to do what stone masons and carpenters do for a living.

Don't presume that because there was imperial rule, everybody had to be miserable.

1. What does the great wall have to do with Forbidden Palace?2. Just because it's contracted out to private merchants and there are skilled engineers/architect/masons working on the forbidden palace, doesn't mean that the majority of the laborerers aren't low waged peasant farmers. You think the masons and engineers hauled the stones themselves?

"The reason the question had been debated for so long is that there were two other competing theories. One, now almost entirely discredited, is the theory that proposed the liquid layer at the ice surface not to form spontaneously, as is now believed, but rather by"

"As is now believed"... that doesnt sound pretty darn certain, does it? And the rest of the article is equally tentative.

"The reason the question had been debated for so long is that there were two other competing theories. One, now almost entirely discredited, is the theory that proposed the liquid layer at the ice surface not to form spontaneously, as is now believed, but rather by"

"As is now believed"... that doesnt sound pretty darn certain, does it? And the rest of the article is equally tentative.

Don't be that guy. There are unanswered questions in the universe. You just found out that this isn't one of them. Now go, and celebrate your new knowledge.

Demonstrates that "ancient man" doesn't mean "idiot men". Now can I assume that going down hill wasn't problematic?

Referring to the most sophisticated civilisation in the 16th century as ancient is pretty insulting to be honest.

This comment is fascinating in that it reveals some other axe to grind in regard to portrayal or perception of China. Certainly the comment should not be elicited simply from something 500 years old being called "ancient".

Ironically, I would agree that China is often portrayed negatively by westernized democracies right now. But come on, pick your battles! Harping on something like this makes it harder to address the topic when actually valid.

Now, another question is why when the Chinese civilization is so old and the western civ is so young, did the western Civ out pace the Chinese technology wise?

There are huge swaths of books and research dedicated to this topic.

Short answer: War.

Europe's constant wars and fights between each other spured technology growth in a time when the Chinese Civilization reach unification. There are a lot of groups all over China that are not Chinese, but for the most part all of China unified under one government and inovation slowed.

Instead of investing in technology, the rich kept accumulating more wealth instead of stirring up innovation.

Constant war in europe created;Faster, stronger, and larger ships because constant sea battles caused each side to keep trying to out do the otherStronger lighter armor because armies still had to get around and be protectedStronger and more fortified forts, castles, and general building structure While gun powder came from China, Europe took to making many more and stronger guns to continue fighting.

Technology such as planes were not created for war, but were certainly industrialized and mass produced for war.

There is a superb book "Why The West Rules ~ For Now: The patterns of history and what they reveal about the future" by Ian Morris. Ian Morris is an academic and, unsurprisingly, the book is brilliantly researched with a long bibliography and index.

The book is long but extremely readable.

Short Answer: Ian Morris does not reach the conclusion that it's war. And he provides some excellent arguments along with documented evidence for his hypothesis.

There is a superb book "Why The West Rules ~ For Now: The patterns of history and what they reveal about the future" by Ian Morris. Ian Morris is an academic and, unsurprisingly, the book is brilliantly researched with a long bibliography and index.

The book is long but extremely readable.

Short Answer: Ian Morris does not reach the conclusion that it's war. And he provides some excellent arguments along with documented evidence for his hypothesis.

Thank you, I shall have to read this book and come back at a later date to give my rebutal...

Looking at an off hand cursory review of the book on amazon and Nytimes,

I would offer to say that China found fossil fuels first. If you look at the natual gas, coal, and most resources Morris cites, China has more much more than Europe.

However, China lacked the motivation to gather the resouces and distribute through out the land compared to Europe.Europe was motivated to war with each other. Each group gathered all available resources as quick as possible while China, being so big had a more difficult time distributing the resources to the people. Gathering of resouces was more controlled by one government instead of several governments trying to fight each other.

While Morris touches on Zheng He's exploration and his "finding" of Africa and possibly North America, China at the time lacked the political will to conquer the other civilization and gather more resources.

As you may know form Europe's great age of exploration and "finding" America was based on trying to find gold to fund further war. Or get more trade to fund the war. Another motivation was that the spice route was blocked, Crusades did not work very well, and they were trying to find another route. More fighting.

Now, another question is why when the Chinese civilization is so old and the western civ is so young, did the western Civ out pace the Chinese technology wise?

There are huge swaths of books and research dedicated to this topic.

Short answer: War.

Europe's constant wars and fights between each other spured technology growth in a time when the Chinese Civilization reach unification. There are a lot of groups all over China that are not Chinese, but for the most part all of China unified under one government and inovation slowed.

Instead of investing in technology, the rich kept accumulating more wealth instead of stirring up innovation.

Constant war in europe created;Faster, stronger, and larger ships because constant sea battles caused each side to keep trying to out do the otherStronger lighter armor because armies still had to get around and be protectedStronger and more fortified forts, castles, and general building structure While gun powder came from China, Europe took to making many more and stronger guns to continue fighting.

Technology such as planes were not created for war, but were certainly industrialized and mass produced for war.

"Like the fella says, in Italy for 30 years under the Borgias they had warfare, terror, murder, and bloodshed, but they produced Michelangelo, Leonardo da Vinci, and the Renaissance. In Switzerland they had brotherly love - they had 500 years of democracy and peace, and what did that produce? The cuckoo clock" Harry Lime, The Third Man

My dad, former army corp of engineer officer, had a saying "when your hands get tired, your brain goes to work".

Humans, like all biological creatures, are analog machines. We look for the path of least resistance.

Put enough folks together doing a shitty task, and someone will eventually get a bright idea on how to make it easier.

We've done our ancestors an injustice by assuming they were idiots.

The thing about manual labor, though is it's a double-edged sword. A group of manual laborers can figure out ways to make a task easier. But, as long as manual labor is still cheap, then there won't be major innovations in automation.

EG: Heron was on the verge of inventing the steam engine in roman times. But, since slave labor was so cheap, there was no need for it. So, he never pursued it aside from making a novelty toy out of it.

Monumental tasks can be accomplished quite easily when you rule with the divine right and you have a mass of poor peasants looking for work.

From what I have read in my limited capacity in researching the economic system of ancient China, the people who built these were likely free, specialized workers employed by the central government or militia members in suburban Beijing. The Ming great wall was partly constructed by contracted private merchants, partly by the solders who were garrisoned there - Imagine how difficult it would be for uneducated farmers to be taught to do what stone masons and carpenters do for a living.

Don't presume that because there was imperial rule, everybody had to be miserable.

I have been the Forbidden City in the mid-2000. And I have examined the stones of many imperial structures from other cities. Each piece of stone were crafted by highly skillful craftsmanship. People must have done this type of work in their whole life to qualified for the jobs. If one is not up to that level of skill and he accepted the job. He is looking for trouble and he might lose of own life because of a tiny and unintentional mistake he made. A regular farmer could not be skillful enough to handle such fine craftsmanship.

So what craftsmanship are we talking about here? Each piece of stone must be lined up so perfectly and smoothly polished. It must match to the one on top, left, right, and one below it. Do this all by hands. You could find each craftsman's signature on every single piece of stone at the bottom right corner and this is in case something went wrong such as the stone did not line up good enough to its official standard and that person could be located by the officials. "This is you, there's your name on it." "I am innocent, I need a lawyer. A dream team.. Please?" "I take the fifth." These officials don't fool around and so were the guys who were doing that.

Quote:

Icy routes were laid for sliding super-size stones.

I was surprise there was no mentioning on water buffalo and horses in the articles. Those were the main "movers" in those old days other than pull and push by human workers.

I was surprise there was no mentioning on water buffalo and horses in the articles. Those were the main "movers" in those old days other than pull and push by human workers.

Apparently it's because China had difficulties breeding horses domestically (source), thus making it impractical to use horses in anything other than military and message sending. I find it extremely ironic that they had to pay great sums of gold/silver/silk to nomads for the horses they would use to defend against quite possibly the same nomads.